A study published recently in the Proceedings of the National Academy of Sciences contemplates the places our minds go – figuratively speaking – when they wander. In an effort to understand how our electric signals move throughout different regions of the brain when in different states (focused, fixated, wandering), researchers from UC Berkeley designed an experiment to measure brain activity.
Over two dozen study participants had their brain activity measured with an electroencephalogram (EEG) while they performed certain tasks requiring various levels of attention. The data collected from these tests showed that all of the participants experienced increased alpha brain waves in the prefrontal cortex when their thoughts jumped from one topic to another. Alpha waves are slow brain rhythms with frequencies of 9 to 14 cycles per second. The increase of these types of brainwaves suggests the occurrence of unconstrained, spontaneous thought.
A different kind of brain wave, called P3, was seen in the parietal cortex when study participants seemed to be not paying attention to the task. Both of these findings help construct an electrophysiological signature typical of our brains in certain states.
"For the first time, we have neurophysiological evidence that distinguishes different patterns of internal thought, allowing us to understand the varieties of thought central to human cognition and to compare between healthy and disordered thinking," said study senior author Robert Knight, a UC Berkeley professor of psychology and neuroscience.
"This could help detect thought patterns linked to a spectrum of psychiatric and attention disorders and may help diagnose them," adds study lead author Julia Kam, who is an assistant professor of psychology at the University of Calgary.
EEG technologies are especially helpful because they can show us signals that occur in the brain even before patients might be aware of the repercussions of said signals. This could be useful in understanding the patterns of mind-wandering and the relation between certain patterns and disorders, particularly amongst children.
"Babies and young children's minds seem to wander constantly, and so we wondered what functions that might serve," notes co-author Alison Gopnik, a UC Berkeley developmental psychologist and philosophy scholar. "Our paper suggests mind-wandering is as much a positive feature of cognition as a quirk and explains something we all experience."
But understanding the flows of free thought could be equally as useful for those with ordered and disordered thinking. "The ability to detect our thought patterns through brain activity is an important step toward generating potential strategies for regulating how our thoughts unfold over time, a strategy useful for healthy and disordered minds alike," concludes Kam.
Sources: PNAS, Eureka Alert
